This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To explore a noninvasive method to objectively assess changes to collagen in the pregnant cervix in order to develop a method to learn about abnormal cervical change (e.g. preterm birth and failed post-term inductions of labor). The preterm birth rate has not changed in a century. Methods of prediction (i.e. ultrasound assessment of cervical length) are of limited use because there are no options for prevention;by the time the cervix has changed grossly, it is too late. Biochemical, molecular, and biomechanical studies suggest that collagen is primarily responsible for cervical. Unfortunately, there is no practical and simple way to characterize early changes to cervical collagen. We propose quantitative ultrasound (backscatter) to evaluate the collagen structure of the cervix;a solid and noninvasive method of assessment would promote a comprehensive understanding of the remodeling process (normal and abnormal) in pregnancy. We are currently acquiring hysterectomy specimens from Rhesus monkeys dedicated to other research projects. We acquire data with a tiny (3.3mm) ultrasound transducer, sampling from the cervical canal in the four cervical quadrants (12:00, 3:00, 6:00 and 9:00) at depths of 2mm, 4mm and 6mm. At each location we obtain raw radiofrequency (RF) echo signals, with the beams steered from 0o orientation in increments of 5 o up to +45o. We administer misoprostol (a standard agent used to ripen the cervix prior to gyn procedures or induction of labor) to some animals and compare those measurements to those taken from the other animals (without misoprostol). We plan to scan a group of nonpregnant Rhesus females on menstrual cycle days 1, 7, 14, and 21 to provide an idea of biological variability with hormonal fluctuations. Ultimately, we plan to follow animals throughout gestation, scanning monthly (weeks 6, 10, 14, 18, 22 and 2 weeks postpartum) to create a nomogram of cervical changes to collagen throughout pregnancy. This project is recently initiated;we are currently acquiring preliminary data in preparation for a funding application. This project relies on WNPRC Research Services.